Alert archive / Florida / Flash Flood Warnings in 2013

Flash Flood Warning 39, NWS Tallahassee, FL

August 18, 2013Bay County, Walton County, Washington County, Florida

NWS Tallahassee, FL issued this flash flood warning at Aug 18, 2013, 12:50 PM CDT for Bay County, Walton County, Washington County, Florida. It was in force for 3 hr. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 18, 2013, 12:50 PM CDT (17:50 UTC)
Expired: Aug 18, 2013, 3:45 PM CDT
In force: 3 hr
Issued by: NWS Tallahassee, FL
Area: Storm-based polygon
Flood severity: None

Counties Bay County, FL, Walton County, FL, Washington County, FL

The radar

The Eglin Afb radar (KEVX), 20 km from the middle of the area, began a volume at 17:53 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Aug 18, 2:00 PM CDT	FLASH FLOOD	Vernon, FL	HEAVY RAINFALL CAUSED WIDESPREAD FLASH FLOODING WITH IMPACTS MAINLY TO ROADS ACROSS WASHINGTON COUNTY. WATER OVER NUMEROUS ROADS...WITH DAMAGE TO MANY OF THE DIRT ROADS ACROSS THE COUNTY. SOME HOMES MAY HAVE BEEN AFFECTED BY WATER.
Aug 18, 3:00 PM CDT	FLASH FLOOD	Grayton Beach, FL	WATER REPORTED OVER NUMEROUS SOUTH WALTON COUNTY ROADS PER WALTON ALERT FACEBOOK PAGE. SOME ROADS WERE UNDER MORE THAN A FOOT OF WATER IN DEVELOPED AREAS NEAR THE COAST...WITH WATER WASHING UP CLOSE TO SOME HOMES ON SECONDARY ROADS.
Aug 18, 3:00 PM CDT	FLASH FLOOD	Vernon, FL	HEAVY RAINFALL CAUSED WIDESPREAD FLASH FLOODING WITH IMPACTS MAINLY TO ROADS ACROSS WASHINGTON COUNTY. WATER OVER NUMEROUS ROADS...WITH DAMAGE TO MANY OF THE DIRT ROADS ACROSS THE COUNTY. SOME HOMES MAY HAVE BEEN AFFECTED BY WATER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 5.8 hours before the alert went out and 171 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1173 J/kg
Mixed-layer CIN: -44 J/kg
Mixed-layer LCL: 709 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 162 m²/s²
0-3 km storm-relative helicity: 165 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 8.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

889 
WGUS52 KTAE 181750
FFWTAE
FLC005-131-133-182045-
/O.NEW.KTAE.FF.W.0039.130818T1750Z-130818T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1250 PM CDT SUN AUG 18 2013

THE NATIONAL WEATHER SERVICE IN TALLAHASSEE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WESTERN BAY COUNTY IN THE PANHANDLE OF FLORIDA...  
  SOUTHERN WALTON COUNTY IN THE PANHANDLE OF FLORIDA...  
  THIS INCLUDES THE CITY OF SANTA ROSA BEACH...
  WASHINGTON COUNTY IN THE PANHANDLE OF FLORIDA...
  THIS INCLUDES THE CITY OF VERNON...

* UNTIL 345 PM CDT

* AT 1242 PM CDT...THE NATIONAL WEATHER SERVICE HAS DETECTED FLASH   
  FLOODING FROM THUNDERSTORMS OVER THE WARNED AREA...AS WELL AS      
  ANTECEDENT FLOODING FROM EARLIER RAINFALL WHICH WAS CAUSING SOME   
  ROADWAYS TO WASH OUT AND BECOME IMPASSABLE. RUNOFF FROM THIS        
  FLOODING AND ANY ADDITIONAL RAINFALL MAY TAKE SEVERAL HOURS TO     
  COMPLETE AND WILL ONLY SERVE TO EXACERBATE THE CONDITION.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO NEW HOPE...
  SEAGROVE BEACH...SEASIDE...GRAYTON BEACH...BLUE MOUNTAIN BEACH...
  MILLERS FERRY...HOLMES VALLEY...SYLVANIA...SMYRNA...SPRING
  HOLLOW...WHITEHEAD CROSSROADS...BROCK CROSSROAD...RIVERSIDE...
  WAUSAU...TURQUOISE BEACH...SEMINOLE HILLS...RED HEAD...RED BAY...
  PORT WASHINGTON...POPLAR HEAD...PINE LOG...LAIRD...KNOX HILL...
  HINSONS CROSSROADS...GREENHEAD...FREEPORT...FIVE POINTS...EBRO...
  BUNKER...BRUCE AND LIVE OAK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE AWAY FROM RISING WATER TO HIGHER GROUND! MOST FLOOD DEATHS OCCUR
IN VEHICLES. DO NOT ATTEMPT TO DRIVE THROUGH FLOODED ROADS.
REMEMBER...TURN AROUND...DON'T DROWN.

&&

LAT...LON 3042 8630 3041 8628 3043 8627 3043 8624
      3039 8615 3039 8613 3045 8617 3047 8623
      3061 8605 3071 8581 3073 8557 3056 8554
      3034 8583 3021 8587 3037 8631 3040 8632

$$

17-GOULD

The office that day

Everything else NWS Tallahassee, FL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 17, 8:49 PM CDT	River Flood Warning	TAE	Calhoun	9 days
Aug 17, 11:00 PM CDT	River Flood Warning	TAE	Holmes, Washington	9 days
Aug 17, 11:00 PM CDT	River Flood Warning	TAE	Walton	12 days
Aug 18, 1:45 AM CDT	Rip Current Statement	TAE	Bay, Gulf, Walton	17 hr
Aug 18, 5:05 AM CDT	Flash Flood Watch	TAE	Bay, Calhoun, Dixie, Franklin, Gadsden, Gulf and 10 more	38 hr
Aug 18, 5:41 AM CDT	Special Marine Warning	TAE		2 hr
Aug 18, 6:37 AM CDT	River Flood Warning	TAE	Walton	13 hr
Aug 18, 9:08 AM CDT	River Flood Advisory	TAE	Calhoun	20 hr
Aug 18, 10:18 AM CDT	Special Marine Warning	TAE		27 min
Aug 18, 10:25 AM CDT	Special Marine Warning	TAE		50 min
Aug 18, 11:10 AM CDT	Special Marine Warning	TAE		50 min
Aug 18, 11:21 AM CDT	Areal Flood Advisory	TAE	Walton	3 hr
Aug 18, 11:40 AM CDT	Areal Flood Advisory	TAE	Franklin	3 hr
Aug 18, 12:00 PM CDT	Severe Thunderstorm Warning	TAE	Franklin, Wakulla	45 min
Aug 18, 12:08 PM CDT	Special Weather Statement	TAE	Liberty	52 min
Aug 18, 12:14 PM CDT	Areal Flood Advisory	TAE	Wakulla	3 hr
Aug 18, 12:17 PM CDT	Areal Flood Advisory	TAE	Liberty	3 hr
Aug 18, 1:16 PM CDT	Flash Flood Warning	TAE	Franklin, Wakulla	3 hr
Aug 18, 1:48 PM CDT	Flash Flood Warning	TAE	Holmes, Jackson, Washington	3 hr
Aug 18, 1:54 PM CDT	Severe Thunderstorm Warning	TAE	Walton	51 min
Aug 18, 3:57 PM CDT	Flash Flood Warning	TAE	Bay, Holmes, Jackson, Walton, Washington	3 hr
Aug 18, 4:09 PM CDT	River Flood Warning	TAE	Gadsden, Leon	11 days
Aug 18, 4:09 PM CDT	River Flood Warning	TAE	Gadsden, Leon	13 days
Aug 18, 4:37 PM CDT	Severe Thunderstorm Warning	TAE	Jefferson, Madison, Taylor	38 min
Aug 18, 5:22 PM CDT	Special Weather Statement	TAE	Jefferson	53 min

Nearby

Flash Flood Warnings in Florida, 2013 Every flash flood warning in 2013

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.